Plug



1.1 is a perspective view of a plug showing my new design;

1.2 is a front view thereof;

1.3 is a back view thereof;

1.4 is a left view thereof, wherein the right view is identical to the left view;

1.5 is a top view thereof; and

1.6 is a bottom view thereof. 

CLAIM The ornamental design for a plug, as shown. 